Production of steam in the manufacture of phosphorus acids from phosphorus and steam



Sept. 22, 1931.

VV.VVH D ET'AL PRODUCTION OF STEAM IN THE MANUFACTURE 0F PHOSPHORUS ACIDS FROM PHOSPHORUS AND STEAM INVENTORS B" Mam@ ATTORNEYS Patented Sept. 22, 1931 MANY, AssrGNoRs rro I. G. raanamnnusrain'gearsiiens Lscnieirr", or raam;-

FoRT-oN-THEWMAIN, GERMANY, A ooaroRAfrlroir 'oF'eERMNj/rif PRODUCTION OF STEAM IN Application med November 2e, 192s, sei-iai Noli isiees,

In the preparation of phosphorus acids and hydrogen from phosphorus and steam large quantities of steam are required.

lVe have now found that a large proportion of the steam so required can be pro-duced by effecting the condensation of the resulting phosphorus acids with the aid of a Wateroperated cooler or condenser in which the reaction gases do not come in direct contact with lhe cooling Water, maintained at a temperature of 100 C. or higher, which at the same time serves as a generator for steam of atmospheric or higher pressure. The expressions cooler or condenser when used in the Jfollowing description and the term indirect heat exchange relation with Water as used in the appended claims only refer to such coolers or condensers in which direct contact of the gases leaving the reaction vessel with the cooling Water is avoided. The materials Which may preferably be used for the Walls of such a condenser are tin bronze, aluminum bronze, ferro-silicon or the like.

Additional quantities of steam needed for the process can be produced by passing the mixture of excess steam and hydrogen issuing Jfrom the said condenser through a second wateroperated cooler or condenser which is maintained at a temperature below 100 C. and operates as a steam-generating apparatus under a pressure lower than that of the at mosphere. The steam generated in this apparatus is then compressed to the pressure requisite for the interaction of phosphorus and steam. During this compression the steam becomes superheated, which is advantageous in the reaction with the phosphorus. Occasionally, for example When cheap electrical energy for compressing and superheating the steam generated under a pressure loW- er than that of the atmosphere is available, it may be advisable to omit the first stage entirely and pass the reaction mixture directly through the condenser maintained a ternperature below 100 C.

According to this invention considerable amounts of heat are recovered and utilized for the production of steam. Not only is the sensible heat contained in the hot gases leaving the reaction chamber utilized, but also the 'ren MANUFaorUaE or riiosrnoitusncrns FRM PrrosrnoausTerri),,slirjafifgm.'" 'f r nuermnyreeember'3,-*192a'f iheat ot thathemicat combination ofthe'water vapour with phosphorus pentoxideraccordng tol the equation =B2Q5I'3HO.=. 2H3P0 which takes fplace uabov.; ,100@ .1. also the heat Zof .condensation of. the Waterfva'po'r. required therefor:andfoff the phosphorus pentoxid'e.l l. E @The L following-:examp-lefiwill :further illus.- -trate hW-ithisdnvention imaybe, carried .out in practice, but'rthe invention-is inotl limited to this example. The parts are by. Weight.- g 115A mixture; zof; .116,6 `parts of phosphorous .yaporrandcs'lOSO parts f oifstearn is fheated Lto @550 "andpassed ,overoza catalyst .suitable vfor the j oxidation fof 'phosphorus to `phosiplior'ous pentoxide ,1in lthis reaction. approxianately. .2; cubic metres v of' f. hydrogen 1 4,are i disengaged xfo'r reach .kilogram of @phosphorus The gases? :leaving .the .reaction jvessel :with 1 a te'mperature of about5650":;:G.y :are :passed throughca tube4 boiler. made .of a :'coppenaluini-nium-iron allo'yainwhich boiler orthophos phoric acid is@condensed.I and simultaneously :about-,7001 parts oli"- steamfof-a pressure of 115 atmospheres, ri. e.; about 0 per f cent.v 4.of y,the steam required ifor `ithe :reaction i are. a gen- G'Iatdf ":z ,L ,i '.2 Liri t i511 'f :Ther remainingy 1 Vmixture of hydrogen l and Water vapor is passed'throughianotheruconzdenser, in Which-.the #wateryv'apsor v'is fcon densed. The hydrogen leaving fthis con denser may'be employedfor other purposes.

The second condenserI-,amay also be employed as a boiler for the production of steam of 0.3 atmosphere pressure. By compressing the steam so obtained to about 1.2 atmospheres, it is superheated and may then also be employed for the reaction with phosphorus.

The accompanying diagrammatic drawing shows an apparatus suitable for carrying `no out the process here described. A is a. contact vessel containing a catalyst suitable for the reaction. Phosphorous vapors are introduced through the tube D. Two Wateroperated tube condensors B are shown, into m5 which cooling Water is introduced at E, the steam therein generated being taken off through tubings F and admitted thereby into the reaction Vessel A. The lou7 pressure steam generated in the second condenser B is i100 compressed by a compressor C before being introduced into the pipings F. The phosphoric acid and hydrogen produced in the process-.are delivered at l... l -c- A In the-aboe-describedmanner large p'roportions of the steam required for thereonversion phosphorus into phosphorous acids by'nige'ans'of steam are produced'in the gaged in the process.Y What we claim is phorus and hydrogen by the interaction"`of phosphorusand. steam, thelstepy of passing l the hotgases issuing from the said lnteraction into indirect heat exchange relation with vf .'Water maintained.,at'awtemperature of -at f least:1 1004"; C., thereby separating Ethe `acids of phosphorus/and simultaneously producf 2 0 ling essential proportions of the'steam needed inthe reaction of atleast atmospheric pres- ,Y sure: from the Water contained in the said condenser, and. allowing the steam: thus prolduced-to interact with further .amounts of ,-2,5 phosphorus. f

21.2.7-In'the vproduction of acids-oi:` phosv 'phorus and hydrogen by the interaction of lphosphorusfand steam, the stepof passing Y the hot .gases issuing 'from the said interactionv into indirectf-heat exchange relation witlifwatermaintained ata temperature of v .at -fleast 100 C.,=thereby separating the acids i lof: phosphorus and simultaneously. producin'g essential proportions of the steam needed .3.5 in the reaction of atleast atmospheric presl surefrom they Water contained lin said condenser, thereupon passing the gasesA issuing y' -i `from the first l'condenser' into .indirctfheat 'exchange relationiwithwater maintained at -a :4 .0 temperatureloelow 100 C., compressing the x45 -our hands;4

steam thus produced, and allowing the' steam 'thus produced f to j 'interact with further amounts of phosphorus.`Vv v t fn testimony whereof We have hereunto set c WILHELM WILD.

if, l GUSTAV WIETZEL. 

